The present invention relates to a method and apparatus for filling viscous dampers, and more particularly to a method and apparatus for filling viscous dampers in which the fabrication of the dampers include an electron beam welding step.
Torsional vibration dampers which comprise an inertia weight carried in a viscous fluid such as silicone are well known, and the present invention relates to a method and apparatus for making such dampers and in particular to a method of filling said dampers with viscous fluid. In accordance with prior methods, the damper was completely secured together by welding or the like with the inertia weight enclosed therein, and with the top of the housing being provided with two holes. These holes are utilized for filling, with one of the holes being present to provide for egress of air and the other of the two holes being present to provide for entering of the viscous fluid. It is very important that the viscous damper be filled with viscous fluid and substantially no air be present within the housing in order to assure proper operation of the damper assembly when absorbing torsional vibrations and the like. It is also advantageous to utilize electron beam welding in the fabrication of the damper as set forth more fully in Canadian Pat. No. 878,847 issued Aug. 24, 1971 for Torsional Vibration Damper.
In view of the high viscosity fluid being placed within the damper assembly, and the close clearances likely to be present between the inertia weight and the housing wall in certain locations during filling, it is difficult to force viscous fluid into the damper housing and fill the space therein. However, it is important to positively assure that all of the air that might otherwise be present within the housing in the completed unit be removed, and that the interior be sealed so as to retain the interior of the housing free from trapped air and the like which would interfere with the proper operation of the damper. The present invention is directed to an improved method of making and filling said dampers in which improvements are provided both with respect to the simplicity of processing and reliability of manufacture.